Environmental Impact Statement Non Technical Summary Bandon River (Bandon) Drainage Scheme Bandon River (Bandon) Drainage Scheme in association with 1 NON TECHNICAL SUMMARY 1.1 DESCRIPTION OF PROPOSED WORKS The proposed works comprising the Preferred Option for the Bandon River (Bandon) Drainage Scheme are generally as follows; • Detailed Site Investigation comprising trial pits, dynamic probes, boreholes, rotary cores and archaeological test trenches; • Deepening of the existing riverbed by 1.8m just downstream of Bandon Weir to 9.5mOD and dredging for 3.6km (to O’Driscoll’s Bridge) at a gradient of 1/1000; • Underpinning of Bandon Bridge; • The replacement of the existing Pedestrian Bridge with a new Pedestrian Bridge; • The provision of flood defence walls at various locations on the right and left banks of the Bandon River through Bandon Town; • The provision of flood defence walls on the left and right banks of the Bridewell River on New Road; • The provision of flood defence embankments downstream of Bandon Town on the right bank and in localised areas along the left bank in Bandon Town; • Improvements to the existing flood defences on the Bridewell River in Bandon Town; • Improvements to the existing flood defences at the Bandon wastewater treatment plant; • The provision of removable flood barriers in particular areas; • The upgrading of an existing culvert and the provision of localised flood defences at the Mill Stream; • The provision of a rock ramp fish pass and fish counter at Bandon weir; • The provision of fisheries mitigation measures within the dredged channel including the provision of a thalweg which will generally emulate the existing riverbed features, in so far as possible; • Miscellaneous ancillary works including local drainage works behind flood defences. The proposed flood defences will comprise a combination of earthen embankments and reinforced concrete walls. It is noted that an existing flood defence embankment located on the right bank of the Bandon River upstream of the existing weir, is currently being improved by the owner. On completion of these improvements, the embankment will become part of the Bandon River (Bandon) Drainage Scheme. 1.2 LOCATION OF PROPOSED WORKS The majority of the proposed works are located on the banks and within the channel of the Bandon River. The works on the river channel extend downstream of Bandon Town for 3.6km as far as a property access bridge across the river, generally referred to as “O’Driscoll’s Bridge”. Proposed works on the banks of the Bandon River extend from the just upstream of the weir on the left bank to 1-1 Bandon River (Bandon) Drainage Scheme in association with just downstream of the wastewater treatment plant on the outskirts of the town along the N71 towards Inishannon. The improvements to the flood defences on the Bridewell River are located in the town centre along Market Quay. The new flood defences on the Bridewell River will be located along the Clonakilty Road to the south west of Bandon Town centre. The proposed works on the Mill Stream culvert are located on the outskirts of Bandon town close to Old Quay Road, off the N71 towards Inishannon. 1.3 ANTICIPATED CONSTRUCTION METHODS The most significant part of the construction activity required in relation to the proposed works will be the dredging of the river bed. The expected volume of dredged material is approximately 150,000m 3 and will be in a mixture of gravel, silts and rock. It is anticipated that the majority of the excavation will be carried out with conventional excavating equipment using excavator buckets with rock teeth, rock ripping and localised use of rock breakers where required. The dredging of the softer materials eg silts, clays, is likely to take place from the river bank, where suitable access is available. The removal of heavier materials, such as gravels, cobbles, boulders and rock will to be carried out from within the channel itself, when flows are suitably low. A portion of the dredged material is likely to be stored on the riverbank within the construction easement for re-use in the proposed works. Dump trucks will be used to remove the dredged material which cannot be re-used from site. Access routes to and from the site and construction easements are detailed in Drawing 401 of Appendix 3A. The construction of the reinforced concrete flood defence walls is likely to be carried out by traditional methods. In certain locations, where there is a possibility of flood water passing underneath the flood defence wall foundations or embankments, either sheet piles or grouting techniques will be required to provide a cut-off. The sheet piles may be metal or plastic and would be driven to the required depth using a piling hammer or similar. The design of the underpinning required at Bandon Bridge will be guided by the detailed site investigation which will take place prior to the construction stage. It is anticipated that the bridge piers are founded on rock and as such the proposed works are likely to comprise of excavation to remove unsuitable material around each of the existing piers, grouting of the retained rock, placing of reinforced concrete around the existing piers and stone cladding (if required) to match existing finish. The removal of the existing pedestrian bridge between the weir in Bandon and Bandon Bridge and the construction of the new pedestrian bridge is also proposed as part of the project. 1.4 CONSTRUCTION PROGRAMME AND SEQUENCING OF PROPOSED WORKS The proposed dredging works are likely to be carried out in the first summer season following commencement of the construction works and it is anticipated that the proposed dredging works will take place over two summer seasons. The proposed fish pass at Bandon Weir will be constructed during the first summer season. During the second summer season, dredging works will be completed and the proposed fisheries mitigation measures will be implemented within the portion of the channel where dredging works will have already taken place in the first summer season. It is likely that the proposed fisheries mitigation 1-2 Bandon River (Bandon) Drainage Scheme in association with measures will be constructed on the remaining portion of the dredged channel during the summer following the final portion of the proposed dredge works. The construction of the proposed flood defences, culverts, drainage works and other ancillary works will be ongoing over the duration of the contract. The actual construction programme will be dependent on the appointed contractor’s works proposals, selected construction methods and the time of year when the contract will be awarded. For the purposes of the Environmental Impact Statement, a 24 month construction period is envisaged. This will include the two 5 month summer periods involving the proposed dredging work. The second part of the fisheries mitigation measure implementation will most likely not take place until the first summer after the final dredging works take place. It is expected that normal working hours would be 8:00am to 6:00pm from Monday to Friday but these working hours are likely to be extended to 7:00am to 9:00pm from Monday to Saturday to facilitate the river dredging work during the summer period. 1.5 TEMPORARY CONSTRUCTION WORKS FACILITIES Prefabricated temporary buildings will be provided for the site workers during the construction works to include welfare facilities and office space as required. Any effluent generated from the welfare facilities will be discharged to the public sewer. Plant and machinery may also be stored at this location. A wheelwash will be provided at exit points from the works site to ensure that vehicles leaving the works area do not carry excess soil and material onto the adjacent public road infrastructure. 1.6 ESTIMATED COST OF PROPOSED WORKS The current estimated construction cost of the proposed works is €9.075 million excluding VAT. Other non-contract costs are estimated at €4.725 million, bringing the total cost of the Bandon River (Bandon) Drainage Scheme to approximately €13.8 million excluding VAT. 1.7 OPERATION AND MAINTENANCE OF SCHEME The main maintenance requirement of the proposed scheme, once it comes into operation, will be in relation to the dredged section of the riverbed. It is anticipated that maintenance dredging will be required at an estimated interval of 5-7 years, depending on the frequency and magnitude of flood events that might occur within the intervening period. Maintenance dredging, when required, will take place during low flow conditions and only deposits visible above low water levels will be removed. No maintenance dredging of deposits below low water level will be required. Maintenance dredging will be carried out in accordance with the OPW Environmental Management Protocols and Standard Operating Procedures which have been drawn up in consultation with Inland Fisheries Ireland. Regular strimming of the proposed embankments will be required to control vegetation growth. Periodic maintenance of the proposed flood defence embankments may also be required on localised sections of the proposed embankment as a result of minor settlement or flood damage. 1.8 IMPACTS ASSESSMENT - HUMAN BEINGS The key issues examined in the Human Beings Chapter include population, employment and economic activity, land-use, residential amenity, facilities and services, tourism, and health and safety. Reference is also made to nuisance impacts on human beings such flooding, dust, noise and traffic. 1-3 Bandon River (Bandon) Drainage Scheme in association with The major settlements within the Study Area include Bandon and Innishannon. Main employers in the area include the Eli Lilly Pharmaceutical Plant, the Laragh IDA Estate, Henry Good Millers and the agri-food based employers in Bandon, Bandon Co-op, Anglo Irish Beef Processors and the local mart.